Bread making apparatus

ABSTRACT

A bread baking apparatus makes dough by kneading raw ingredients tossed into a bread baking case installed in an oven, and baking after fermentation. The object of this invention is to conveniently provide attractive-appearing bread having a specified expanded volume and a prespecified color when baked. Namely, in order to prevent undesirable results, such as expanding more or less than specified in the fermenting process, or being affected by external room temperature and humidity which has penetrated the oven through a glass lid installed on the baking oven, this apparatus is provided with means for detecting fermenting conditions while fermenting, and means for extending the fermenting process time. This apparatus is further provided with baking timer means for defining the color of the final baked product by applying temperature measuring means. Furthermore, air ventilating and heating means, especially uniform heating means during baking are provided in this apparatus to prevent unwanted changes in the baking bread.

This is a division of application Ser. No. 08/160,388 filed Dec. 1,1993, now U.S. Pat. No. 5,415,081.

BACKGROUND OF THE INVENTION

This invention relates to a bread making apparatus primarily fordomestic use, and in particular relates to an apparatus which makesbread, first making dough by mixing and kneading raw materials in abaking case, and then baking the dough after fermentation.

A conventional bread baking apparatus in Japanese patent laid-open No.Showa 63-197417 teaches placing wheat flour, water and yeast into abread baking case set in a closed oven, making dough by kneading, thenfermenting the dough, and baking the desired type of bread.

In this prior art, by pushing down a start button, a sequence programstored in ROM of a microcomputer reads out the bread baking processes inthe following order: primary-kneading process→pause period→secondarykneading process→fermenting process→baking process→cooling process, andthe baking process progresses sequentially, with each process assigned aprescribed time. Each specified processing time in the above-mentionedsequence program is set, with the forming-fermenting process, forexample, being allocated about 50 minutes.

Because the conventional bread making apparatus is so controlled,miscellaneous drawbacks eventually arise as described below.

Namely, at first, an upper portion of a conventional oven has adetachably installed bread baking case which opens upwardly and atransparent glass lid openably installed thereon. This transparent lidallows for easy observation of the bread-making progress. However,despite this convenience, bread making conditions are apt to be effectedby external room temperatures and humidity through the transparentglass. The fermenting dough will expand its volume, especially at highroom temperatures and at high humidity levels, will come in contact withthe lid, and be baked in this manner. The appearance of the baked breadis therefore disagreeable, and removing the bread stuck on the lid mightlead to contamination.

Further, as the dough forming and fermenting periods are allocatedspecified times in the bread making process, and these specified timesare stored fixedly in the sequence program, it is impossible to regulatethe time periods. Accordingly, a shortage in the prespecifiedforming-fermenting time can occur when the apparatus is affected by thetemperature of the ingredients, the external temperature and humidityintroduced through the transparent glass window or other miscellaneousconditions, especially under conditions of low temperature and lowhumidity. The resultant dough-forming and fermenting process isinsufficient, producing bread that has not sufficiently risen during thefermenting process.

The normal expansion of the dough during the fermenting process is themost important point in producing good bread. In order to obtainagreeable-looking bread, there were many problems relating to the colorof the baked bread in the baking process following fermentation and thecooling process that follows baking.

SUMMARY OF THE INVENTION

The present invention has been developed to solve the afore-mentioneddrawbacks, and its object is to provide a bread making apparatusfurnished with a lid made of transparent glass for easily observing thestate of the bread making process, and to enable the production ofwell-formed bread despite a propensity to be affected by externaltemperature and humidity.

In a bread making apparatus according to the first embodiment, a bakingoven, a bread baking case detachably installed in the oven, a lidopenably installed on the opening of the oven and a control means forcontrolling bread making processes comprises:

a mixing and kneading process for tossing raw bread ingredients in thebaking case, kneading them and making bread dough;

a fermenting process for fermenting the dough; and

a baking process for baking the fermented bread dough; the controllingmeans characterized by being provided with:

a fermentation detecting device for detecting the dough expanding nearthe lid during the fermentation process; and

a process-switching device for stopping the fermentation process whenthe detecting device detects the expansion of the dough, and forswitching from the fermentation process to the next baking process.

A bread making apparatus according to the second embodiment is the breadmaking apparatus cited in claim 1, wherein the controlling means ischaracterized by further being provided with:

an extension time-setting means which outputs a signal to thecontrolling means for extending the forming-fermenting time precedingthe baking process;

a process extending means controlling the bread making processes forextending the fermenting time by applying the output from theextension-time setting means; and

the extension-time setting means sets an extension time and the processextending means extends the fermenting process, when the detectingsignal from the fermentation detecting means does not output and thedough does not expand to the specified volume, before the end of the settime of the fermenting process.

A bread making apparatus according to the third embodiment is the breadmaking apparatus cited in claim 1 and 2, wherein the controlling meansis characterized by further being provided with:

a temperature detecting means which detects the temperature in the breaddough;

a color-setting means which sets a color of baked bread; and,

timer means for setting a baking time of the dough that has reached astandard dough temperature corresponding to the color set by thecolor-setting means, after the temperature detecting means detects thatthe dough temperature has already reached the specified standard doughtemperature.

A bread making apparatus according to the fourth embodiment is the breadmaking apparatus cited in claim 1, 2 and 3, wherein the control means ischaracterized by further being provided with:

an air supply means for dehumidifying the baked bread by supplyingexternal air in the enclosed baking oven after the baking process; and

a heating means for intermittently heating the baked bread by repeatingan ON.sup.. OFF action at specified time intervals while applying theair supply means.

A bread making apparatus according to the fifth embodiment is the breadmaking apparatus cited in claims 1, 2, 3 and 4, wherein the baking ovenis characterized in that,

a ring-shaped heater installed on the inner surface of the inner oven isconcentrically placed around the bread baking case, and both ends of theheater at the end of the power inputting end are crossed over eachother, and the low heat-generating portion of the heater is not aroundthe bread baking case.

A bread making apparatus according to the sixth embodiment is the breadmaking apparatus cited in claims 1, 2, 3 and 4, wherein the baking ovenis characterized in that,

a ring-shaped heater installed on the inner surface of the inner oven iseccentrically placed around the bread baking case, and the lowheat-generating portions corresponding to both parallel ends of theheater are located near the bread baking case, and the baking case isuniformly heated in every portion thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a sectional view of a bread making apparatus according tothe first embodiment.

FIG. 2 shows a diagram of a control circuit of the apparatus shown inFIG. 2.

FIG. 3 shows a sectional view of a bread making apparatus according tothe second embodiment.

FIG. 4 shows a diagram of a control circuit of the apparatus shown inFIG. 3.

FIG. 5 shows a process diagram of one embodiment of the bread makingprocesses of the apparatus shown in FIG. 3.

FIG. 6 shows a process diagram of the another embodiment of the breadbaking processes of the apparatus shown in FIG. 3.

FIG. 7 shows a process diagram of another embodiment of the bread bakingprocesses of the apparatus shown in FIG. 3.

FIG. 8 shows a front view of the controller in the bread makingapparatus according to the third embodiment.

FIG. 9 shows a diagram of the baking process of the bread makingapparatus shown in FIG. 8.

FIG. 10 shows the relationship between dough humidity and baking time inthe bread making apparatus shown in FIG. 9.

FIG. 11 shows a control circuit of the bread making apparatus accordingto the fourth embodiment.

FIG. 12 shows the bread making processes of the bread making apparatusshown in FIG. 11.

FIG. 13 shows the main heater of the bread making apparatus according tothe fifth embodiment.

FIG. 14 shows the main heater of the bread making apparatus according tothe sixth embodiment.

FIG. 15 shows the main heater of the conventional bread makingapparatus.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments according to this invention are described in detail withreference to the drawings.

The first embodiment

The first embodiment is described as follows:

In a bread making apparatus A shown in FIG. 1, a cylindrical breadbaking oven 101 is provided. A control board 102 for setting eachprocess time and selecting the preferred baking results is installed onthe front center portion of the oven 101, and the dome-like lid 101 isopenably installed on the upper opening of the oven 101, and then theclosed bread making apparatus is comprised of the oven 101 and the lid103. In this arrangement, the lid 103 is made of transparent glassenabling observation of the internal conditions of the oven, even if itis closed, as the rear end of the lid is rotatably hinged to the oven101 with a hinge pin 103A, and furthermore a grip handle 105 isinstalled on the front side thereof for easy opening of the lid 103.

In the baking oven 101, a cylindrical internal case 108 is installed ona location apart from the bottom wall 106 of the vessel 101 upwardly asmuch as specified space 107, and corresponding downwardly to the lid103, and in the space 107, a base plate 109 for installing a display andswitches corresponding to the control board 102, and a computing circuitboard 110 are installed biased to the front side of the main body 101.

In the main body 101, a support-member 111 is installed vertically onthe bottom plate 106, the inner case 108 is fixed on the support-member111, and in this arrangement a heat-radiating main heater 112 equivalentto an electric heater is installed around the internal surface of theinner case 108 in a ring shape, and the bread baking case 113 openedupwardly is detachably installed on the part 111A equivalent to one partof the supporting plate 111 extruded in the inner case from the centralopening of the inner case 108.

Further a kneading blade 114 for mixing and kneading bread ingredientsin the bread baking case 113 is rotatably provided on the bottom of thecase by a device described later, and an extruded member 115 forpreventing the co-rotation of the dough being clay-like by the agitationwith the kneading blade 114 is fixed on the inner surface of the case113.

While a bearing plate 116 is fixed on the supporting member 111, and therotating shaft 117 driving the kneading blade 114 penetrates thesupporting plate 116, the top end of the rotating shaft 117 is connectedto the kneading blade 114, and the bottom end thereof is rotatablysupported on the support 18 securely installed on the support member 111in the space 107 of the oven 101.

A main motor 11a is enclosed in the space 107, and an output shaft ofthe main motor 11a and the rotating shaft 117 are connected by a pair oftiming pulleys 120, 121 and a timing belt 122. With this arrangement,the kneading blade 114 is driven by the revolving force of the mainmotor 119. A dough sensor 123 comprised of a thermistor for detectingthe dough temperature is installed on the kneading blade 114.

In the oven 101, an external air-inducing path 124 is shaped so that anend portion 124A thereof is opened externally through an opening shapedin the bottom plate, and connected to the bottom portion of a guide duct125 shaped longitudinally along the external side face of the case 108.Installed in the external air-inducing path is an air fan 127 driven bya fan motor 126 which sucks external air, and a fan heater 128 forheating the sucked air is also installed in the downstream of the airfan 127. As a result, the air induced from the path 124 and forced inthe guide duct 125 is blown against the bread baking case 113 through aduct hole 129.

Furthermore, an oven sensor 130 which detects the temperature of the airin the inner case 108 is installed on the inner surface of the case 108,and a thermostat 131 is installed on the outer surface of the case 108.By applying the sensor 130, thermostat 131 and aforementioned doughsensor 123, temperature detection in the multiple processes composingthe bread making process is performed. Namely, as shown in FIG. 2, thedough sensor 123, oven sensor 130, and thermostat 131 are connected tothe controller 132, and the main heater 112, fan heater 128, main motor119 and fan motor 126 are also connected to this controller 132, with amain timer 133 for setting the bread baking time also being connectedthereto.

In addition, a fermentation regulating sensor 134 which detects thetouch of the expanded dough to the guide duct 125 before the doughcontacts the lid 103 during the fermentation process, is installed onthe above-mentioned guide duct 125. As shown in FIG. 2, thisfermentation regulating sensor 134 is connected to the comparativeterminal of a comparator 135 and together with output of a transmitter136, the wave form of a signal input to the comparative terminal isdeformed by the change of resistance induced by the fermentationregulating sensor 134 being "ON". As a result, a touch signal is inputinto the controller 132, and the controller then forcibly controls theprocess to switch to the baking process even if the process is in theprespecified fermenting process.

Next, the action of the bread making processes are described. Thespecified materials are put in the bread baking case 113, the lid 103 isclosed, the start switch 137 of the control board 102 (see FIG. 2) isput on after setting the baking time by applying the main timer 133,then the main heater is put on, and the preheating process begins. Thenwhen the preheating process has ended, the rotation of the main motor119 starts the kneading blade 114 agitating the bread ingredients. Thebaking process then switches to the kneading process by introducing hogair into the bread baking case 113 after the fan motor 126 is driven andthe fan heater is put on, thus molding the dough. These processes areregulated and processed by the controller 132 which controls the excesstemperature produced by the main heater 112 and fan heater 128, so thatthe temperature is maintained within a range that does not kill theyeast, by applying the temperature detected by the thermostat 131. Thebread making processes then proceed to the next fermenting process whilethe temperature of the dough is controlled by the output of the ovensensor 130, after the kneading is finished.

In this fermenting process, the dough gradually expands. As there is adanger that excessively expanded dough will contact with the lid 103,then if the dough touches the fermentation-regulating sensor 134, thecontroller 132 forcibly ends the fermenting process, and prevents bakingof the dough on the lid 103. Eventually, although the dough is fermentedfor the prescribed fermentation time, if it ferments for too long, theprocess switches to the baking process from the time point detected bythe fermentation-regulating sensor 134. And in ending the bakingprocess, only the fan motor 126 is successively rotated, and the processthen proceeds to the cooling process by introducing external air intothe inner case 108.

With these processes, the bread is baked without contacting the lid, andappetizing bread is obtained. It is also unnecessary to clean the lid103 after use.

Second embodiment

The second embodiment according to this invention is described withreference to the drawings as follows. FIG. 3 is a sectional view showingthe construction of a bread making apparatus according to the secondembodiment. FIG. 3 shows a baking vessel main body 1, a plural ofsupporting legs la, an upper baking vessel main body 2, a lid 3constructed openably, a base frame 4, a bearing plate 5, an internalvessel 6, an oven heater 7, a bread baking case 8, a pair of engagingelements 9, 10 and a support plate 11.

Also installed in the external vessel main body 1 are a bearing portion12, an upper rotating shaft 14, a kneading motor 15, a belt 16, a pairof pulleys 17, 18, an output shaft of the kneading motor 19, a lowerrotating shaft 20, a pair of clutch members 21, 22 and a kneading blade23.

Further installed on the external vessel main body 1 are a glass window24 of the lid 3, a heat reflective plate 25, an air-suction guide 26, anair-suction port 27, an air-supplying guide 28, an air fan 29, areverse-flow deflecting plate 30, a dough sensor 31, an adiabatic member32, an oven sensor 33 fixed on the internal case 6, an air-suction motor34, a fermentation-regulating sensor 64, a pair of menu selectingbuttons 35, 36 and a start button 37.

In FIG. 3 the numeral 38 is an operating key enabling the extension ofthe forming-fermenting period (hereafter referred to as the "FF period")or cancellation of the extended time. The numeral 39 is a digitaldisplay expressing the forming-fermenting time.

FIG. 4 is a circuit diagram displaying the construction of the controlcircuit 100 of the bread making apparatus according to the secondembodiment, and the same members as those shown in FIG. 3 are identifiedwith the same numerals and the explanations referring to these membersare eliminated.

In FIG. 4, the numeral 41 is a switch exchanging the dough sensor 31with the oven sensor 33, the numeral 64 is the fermentation-regulatingsensor, the numeral 42 is an integrator, the numeral 43 is a comparativecircuit, the numeral 44 is a thermostat, the numeral 45 is avoltage-watching circuit, the numeral 46 is an abrupt-short watchingtimer and the numeral 47 is a microcomputer controlling all members.This microcomputer 47 is composed with RAM, ROM and I/O ports and A/Dconvertors. The control program performing the bread making operationand miscellaneous required data are stored in the ROM.

The numeral 48 is a modulator feeding back the heater current of theoven heater 7, the numeral 49 is a relay circuit turning on or off theheater current of the oven heater 7, and the numeral 50 is a triaccontrolling the heater current of the oven heater 7.

The numeral 51 is an amplifying circuit and the numeral 52 is a speakerwhich discharges an alarm. The numeral 53 is a relay circuit controllingthe air-suction for controlling the on/off operation of the air-suctionmotor, and the numeral 54 is a relay circuit controlling the air-suctionmotor for controlling on/off operation of the kneading motor 15.

The numeral 55 is a power source circuit of the bread making apparatus,and supplies AC power to the oven heater 7, air-suction motor 34 andkneading motor 15, together with converting the primary AC power sourceinto DC power source for the control circuit.

The numeral 60 is an operating panel, and the menu selecting button 35,the menu setting button 36, the start button 37 and the setting key 38for setting and regulating the forming-fermenting time are installedthereon. The numeral 39 is a digital displayer.

FIG. 5 is a process diagram showing the bread making process controlledby the sequential program stored in ROM of the microcomputer 47 in thecontrol circuit of the bread making apparatus according to the secondembodiment. FIG. 5 shows, between time t0 to t3, or from time t0 to t4,the total bread making process from the time the start button 37 ispushed on, to the time the cooling process ends. In addition, the periodfrom t0 to t1 shows the duration where the setting key 38 is receivable,enabling extension of the forming-fermenting time by manipulating theoperation key 38. The period from t0 to t2 shows the period extendingthe forming-fermenting time, or the period enabling cancellation of theextended forming-fermenting time.

Namely, in the bread making apparatus according to the secondembodiment, the period between time t0, where the bread making processstarts by pushing the start button 37, and the time t1 starting the "FFperiod" usually specified as 50 minutes, is the period capable ofreceiving the operation key 38, and after reception of the key 38, the"FF period" usually specified as 50 minutes is further extended for asmuch as 30 minutes. Then when the extended "FF period" comes to an end,it is possible to cancel the extended "FF period."

FIG. 6 is a process diagram which shows other bread making processesstored in ROM of the microcomputer 47 in the bread making apparatusaccording to the second embodiment of this invention. In thisembodiment, period starting from the time t0 (the bread making processstarts by pushing on the start button 37) ending at the "FF period" isthe period able to receive the instructions of the forming-fermentingperiod operation key 38, and in accordance with numbers activating thekey 38, the "FF period" is extended as much as 10 minutes. Further, byactivating the key 38 by a specified number of times (for example, thekey 38 is activated four times), the extended time of the "FF period"returns to zero.

FIG. 6(a) shows a process diagram of the bread making processes in thesituation where the key 38 is pushed only one time. The "FF period" isextended by only 10 minutes, and the cancellation period of the extended"FF period" is limited to the period of time from start time t0 tofinish time of the "FF period" t5. FIG. 6(b) also shows another processdiagram of the bread making processes in where the operation key 38 ispressed two times, extending the "FF period" for 20 minutes, and thecancellation period of the extended "FF period" is limited to the periodof time from start time t0 to the end time t6 of the "FF period". FIG.6(c) shows another process diagram of the bread baking processes wherethe operation key 38 is pressed three times, extending the "FF period"up to 30 minutes, and limiting the cancellation period of the extended"FF period" to the period of time from the start time t0 to the end timet7 of the "FF period".

FIG. 7 shows a process diagram of the bread baking processes accordingto another sequential program stored in ROM of the microcomputer 47installed in the bread baking apparatus according to the secondembodiment.

In this embodiment, the control system is so constructed as to inhibitactivation of the key 38, during the period starting from t0 (beginningthe bread making process by pushing down the start button 37) and endingat t8 (beginning the "FF period"), and also only during the "FF period"(including the extended "FF period", it is possible to extend or tocancel the preset "FF period").

In this case, the same as in the aforementioned embodiment, the "FFperiod" is extended every 10 minutes in accordance with the number oftimes the key 38 is activated. Furthermore, by activating the key 38 aspecified number of times (four times, for example), this control systemis constructed to return the "FF period" to zero. The residual "FFperiod" from the present time to the specified end time is alsodisplayed by hours, minutes and seconds on the display 39, and theresidual "FF period" is continuously counted down.

FIG. 7(a) shows a process diagram of the bread baking processes, inwhich the forming-fermenting time-setting key 38 is not entirelyapplied. The "FF period" is preset to 50 minutes, and the cancellationperiod for the "FF period" is during the "FF period" preset to 50minutes and corresponds to the period starting at time t8 and ending att9. FIG. 7(b) shows a process diagram of the bread baking process, inwhich the forming-fermenting time-setting key 38 is activated only once,the "FF period" is extended as much as 10 minutes, and the cancellationperiod of the "FF period" corresponds to-the "FF period" including theextended period, and corresponds to the period starting from time T8 andending at T10. FIG. 7(c) shows a process diagram of the bread makingprocesses in which the forming-fermenting time-setting key 38 isactivated twice, then the "FF period" is extended for 20 minutes, andthe cancellation period of the "FF period" corresponds to the "FFperiod" including the extended period, and corresponds to the periodstarting from time t8 and ending at t11. FIG. 7(d) shows a processdiagram of the bread making processes in which the forming-fermentingtime-setting key 38 is activated three times, extending the "FF period"as much as 30 minutes, and the cancellation period of the "FF period"corresponds to the "FF period" including the extended period, andcorresponds to the period starting from time t8 and ending at t12.

In the aforementioned embodiments, the forming-fermenting time-settingkey 38 is used to extend and cancel the processing times, but it may bepossible to use the setting key 38 just for setting extensions, and toinstall another cancellation key for cancelling the set process time.

In FIGS. 4, 5 and 6, embodiments extending the forming-fermenting timeby applying the forming-fermenting time-setting key 38 are described,but in each of the embodiments if the fermentation-adjusting sensor 64issues a detection signal, the detection signal takes precedence overeverything, stopping the fermentation process and automaticallycontrolling the process so that it switches to the next baking process.

The third embodiment

The third embodiment of this invention is described as follows. FIG. 8shows an operation panel 81 of a control unit 80 of the bread makingapparatus according to this invention, and the control unit 80 isinstalled in the bread making apparatus A shown in FIG. 1. Namely, thecontrol unit 80 is installed on the front portion of the oven main body101.

The control unit 80 is provided with a display 82 made of liquid crystalindicating cooking time, present time and the like, a plural of settingbuttons 83 setting the color of the bread during the baking process,i.e., light, medium or dark, and a timer controller 84 (timer device)regulating the baking color of the dough by extending the baking processtime t from the standard dough temperature T0 as much as the dough willbecome in the specified baking color set by the setting button 83, areprovided on the operation panel 81 located on the front of the oven mainbody 101. Here the standard dough temperature T0 is a temperature whichproduces bread of a specified color, namely a light color.

The signal obtained by setting any of buttons 83 is input into the timercontroller 84, and the color of the bread surface is determined, eitherlight, medium or dark, in accordance with the set button. In addition tothese baking condition setting buttons, an incremental button 83D and adecremental button 83E are also provided.

Further, on the operation panel 81, a menu button 86 for setting themenu, a cancellation button 87, a start button 88 and a plural ofdisplay lamps indicating the content of these buttons are provided.

The controller 84 is comprised of a printed circuit board and ICs, andincludes CPU, RAM, ROM, a timer and a watch, and connected to the liquidcrystal display 82, the setting buttons 83, the sensors, including theoven sensor 130, the operating buttons for the main heater 112 and thelike, and display lamps with this arrangement, the controller 84controls the specified operations. Namely, when the dough temperature Ttransmitted from the dough sensor 123 reaches the standard doughtemperature T0, the CPU allows the timer to start to count time. Then,when the time counted reaches the after-defined X time or Y timecorresponding to the color specified by a plural of set buttons 83, theCPU stops the baking process.

The working of these operations are described as follows.

First, the volumetrically specified materials such as bread ingredients,water and the other like, are placed in the bread baking case. Then themenu-displaying lamps 89 are set to the preferred conditions (forexample, set at a loaf of bread) by pushing the menu button 86, and thecolor of the bread is set at either light or medium by pushing either ofthe push buttons 83A or 83B, or, by pushing the increase button 83E, thecolor is changed to dark. Although these conditions are not displayed inthe drawing, it is possible to confirm the condition by displaying onthe liquid crystal display by dividing the display in three stepsbetween medium and dark.

After the menu is set, the start button 88 is pushed down. The motor 119then starts to rotate by receiving the signal from the control unit 80,and the driving force of the motor 119 is transmitted to the shaft 117via the pulley 120, belt 122 and pulley 121. Then the kneading blade 114is driven and performs the first kneading. After pausing for a littlewhile, the second agitation is performed, and at last the coolingoperation is performed by the cooling fan driven by the fan motor 126,and the bread making process if finished.

In the above described processes, the baking process progresses asfollows. Namely, as shown in FIG. 9, from time t starting the bakingprocess, the dough temperature T0 of the inner portion of the dough isalways detected by the dough sensor 122, and monitored by the controlunit, and when the CPU detects that the dough temperature T has reachedthe standard dough temperature T0, namely, the dough temperaturecorresponding to a light color, then the timer starts to count time.

If a light bread color is selected with the setting button 83 (namely,the set button 83A is pressed down) and the selected color is the sameas the specified color, the baking process stops when the doughtemperature T reaches the standard dough temperature T0.

When a "medium" bread color is selected with the setting button 83B, thebaking process stops at time t2 counted X times from the time t0 thatthe dough temperature T reaches the standard dough temperature T0 (thisprocess between time t and time ti is shown as "process M" in FIG. 9).

Also when a "dark" color is selected with the setting button 83C, thebaking process stops at time t3 counted Y times from the time t0 thatthe dough temperature T reaches the standard dough temperature T0 (thisprocess between time t and t2 is shown as "process D" in FIG. 9). Aftereach of L, M and D processes has stopped, the cooling process begins andeach end time of the cooling process is programmed the same as time t3.

The relation between X times and Y times is in fact X<Y, and even ifthere are variations in the quality and combinations of the rawingredients, it is possible to bake with specified difference and ifspecified at the same color, it is also possible to bake until the samecolor. The baked condition is explained as follows, by applying thetemperature rise diagram show in FIG. 10. When a light color has beenselected, the dough is baked at the standard dough temperature T0, afterthe baking time t0. When medium or dark are requested, time countingstarts from time t0, and after the counted time X and Y, the bakingcondition becomes either medium or dark.

As only the elapsed time X=t1-t0 and Y=t2-t0 are specified in thisembodiment, the color of the surface of the bread is not dependent uponthe quantity and combination of the ingredients, but only upon theelapsed baking time. As a result, it is always possible to obtain breadhaving a consistent color.

The fourth embodiment

The fourth embodiment of this invention is described as follows. FIG. 11shows the control section of the bread making apparatus A show in FIG. 1according to this invention.

In FIG. 11, the numerals which are the same as those shown in FIG. 2 arenot explained. Herein, the numeral 139 is a subtimer. This subtimer 139is provided for intermittently activating the fan motor 128 and/or mainheater 112.

The bread making workings are explained as follows. The specified breadingredients are placed in the bread baking case 113 and the lid 103 isclosed. The baking time is set by applying the aforementioned main timer133. By pushing the start button 137 on the operation board 102, themain heater 112 is turned on and the preheating process begins. Whenthat process ends, the main motor 112 starts to drive the kneading blade114 and the ingredients are kneaded. The fan motor 126 then starts torotate and hot air heated by the fan heater 128 is supplied into thebread baking case 113. The kneading process then starts, and the doughis made. In this case, these processes progress under a temperaturelower than that at which yeast is killed, by controlling the heatingtemperatures of the main heater 112 and the fan heater 128 by applyingthe controller 132. After the kneading process ends, the fermenting andbaking processes begin while the dough temperature is controlled by theoutput of the oven sensor 130.

When the above-mentioned baking process ends, the bread making processswitches to the final cooling process by activating only the fan motor128, and introducing external air into the inner oven case 108. In thiscooling process, the bread is gradually cooled by intermittently drivingthe fan heater 128 and/or the main heater 112 at specified periods (forexample, by driving for 2 seconds and stopping for 2 seconds) byapplying the subtimer 139, without abrupt cooling by introducing coldexternal air. Thus an abrupt temperature drop after switching to thecooling process is preventable, and as the temperature of the breadbaking case 113 does not suddenly become lower than the surfacetemperature of the bread, then it is also possible to prevent thefreezing of the vapor generated from the surface of the bread on theinternal surface of the bread baking case 113 in the cooling process. Byalso correctly setting the cooling period and intermittent ON-OFF timeof the fan heater 128, the surface temperature of the bread after theend of the above-mentioned intermittent heating generously drops, andbread with a desired surface hardness is obtained by this effectiveafter-cooling.

The fifth embodiment

The fifth embodiment of this invention is described with reference tothe drawings as follows. FIG. 13 shows the main heater 112 of the breadmaking apparatus A according to this invention.

The bread baking case 113 is placed in the inner oven case 108, andaround the inner surface of the oven case 108, the main heaterequivalent to the electric heater radiating heat is so installed as toencircle the bread baking case 113. The kneading blade 109 agitating theingredients in the baking case 113 is rotatably installed therein so asto be driven by not shown a driving device

In the above arrangement, the bread baking case 113 is a cylindricalcase having a bottom plate, and the main heater 112 concentricallysurrounds the case 113 by shaping a ring, and both end portions 112A,112A connected to the power source circuit (not shown) are supported onthe support member 112 crossing each other. With this arrangement, thehigh heat-generating portion 112B of the heater 112 is able tocontinuously surround the bread case 113. By adopting this heaterarrangement, only the high heat-generating portion 112B of the heater112 perfectly surrounds the bread baking case 113, uniformly heating thecase 113, and unevenness in the bread baking is accordingly prevented.

The sixth embodiment

FIG. 14 shows the sixth embodiment. In this embodiment, the center P1 ofthe bread baking case 113 is shifted from the center P2 of thering-shaped heater 112. Both ends 112A, 112A of the heater 112equivalent to low heat-generating portions are placed near the case 103and a high heat-generating portion 112B is placed apart from the case103. By adopting this arrangement, the heat quantities radiating to thebread baking case 103 corresponding to the low heat-generating portions112A, 112A of the heater increase and conversely the heat quantitiesradiating to the baking case 103 corresponding to the highheat-generating portion 112B of the heater decrease. As a result, theheat quantities radiating to the bread baking case 113 are uniformlyequalized against all external surfaces of the baking case, andfavorable heating effects, similar to the fifth embodiment, areobtainable. FIG. 15 shows heat distribution where both centers of theheater 112 and the bread baking case 113 are concentric. The X portionof the case 113 is heated to the maximum, and the Y portion is heated tothe minimum. In this embodiment, this arrangement is applied to theround-shaped baking case, but it is possible to obtain the same effectwith a square-shaped case.

By applying the first embodiment, it is possible to detect the expansionof the dough by the sensor before the dough will touch to the lid, andto let forcibly the process transfer to the next baking process even ifthe process is on the way of the fermenting process, when the dough willgrow up to excess expanded condition due to the effect of the externaltemperature or humidity. As a result, it becomes possible to bake up thebread in good condition and to prevent the contamination of the lid.

With applying the second embodiment, if the fermentation time is short,it is possible to extend the forming-fermenting time and to discontinueany imperfect bread making process caused by a progression to the nextprocess even where the forming-fermenting was deficient.

By applying the third embodiment, it becomes possible to bake breadhaving a consistent color despite variations in quantity and combinationof the raw ingredients. It is further possible to accurately obtainbreads of differing colors by setting the standard dough temperature, byproviding timer means setting the baking time starting from the timethat the dough reaches the standard dough temperature according to thecolor set by the time setting means after the temperature detectingmeans has detected the dough temperature has reached the standardtemperature.

By applying the fourth embodiment, in the cooling process followingbaking, the supplemental heat is supplied intermittently and parallelyby ON-OFF operations of the heating means, together with the cooling bythe air supply means, and as the temperature drop in the bread bakingcase immediately after transferral to the cooling process is prevented,it becomes possible to prevent frosting of the steam due to thetemperature difference with the bread. Also, by the relative adjustmentof the ON-OFF time of the heating means and the cooling time, it ispossible to produce bread having the most favorable surface hardness,and to obtain delicious bread.

What is claimed is:
 1. Bread making apparatus comprising;a bread bakingoven having an upper opening; a bread baking case detachably installedin said baking oven; a lid installed on said baking oven to selectivelyopen and close said upper opening; control means comprising a microcomputer and read-only-memory for storing and executing a programmedsequence of steps including a primary kneading step, a pausing step, asecondary kneading step, a fermentation step and a baking step, saidcontrol means further comprising temperature detecting means fordetecting the dough temperature, color setting means for setting thedesired color of the processed bread, and timer means for setting a newbaking time starting from the time when a specified standard doughtemperature corresponding to said baked color set by said color settingmeans is reached after detection by said temperature detection means ofthe dough reaching a preselected temperature.
 2. A bread makingapparatus as claimed in claim 1, wherein said control means is furtherprovided with air supply means for supplying air into said enclosedbread baking oven for dehumidifying said baked bread, and heating meansfor intermittently heating said baked bread at specified intervals ofON-OFF action while said air supply means is operated.
 3. A bread makingapparatus as claimed in claim 2, wherein said heating means comprises aheater installed around said bread baking case in a shape of ring-likeform, both ends of said heater being placed at the power inputting sidecrossing each other, whereby lower heat-generating portions of saidheater are not installed around said bread baking case.
 4. A breadmaking apparatus as claimed in claim 3, wherein the center of saidheater is placed at a position shifted from the center of said breadbaking case so that the lower heat generating portions of said heaterplaced near the power inputting portion are more nearly located aroundsaid bread baking case than other higher heat-generating portions ofsaid heater.
 5. A bread making device provided with a bread baking caseinstalled in a baking oven and provided with a lid openably mounted onsaid baking oven, in which bread baking steps including kneading rawingredients to make a dough, fermentation of the dough, baking bread andcooling baked bread are performed sequentially, comprising:temperaturedetecting means for detecting the temperature in the oven before thestart of kneading; preheating control means, which is provided with afirst ROM, for memorizing a plurality of temperature ranges of which thehighest value is a predetermined temperature at which said kneading stepstarts and which successively decrease; means for determining aparticular temperature range to which said detected temperature in theoven belongs, and a second ROM for memorizing duty ratios of currentflow for a heater corresponding to each temperature range; and means forheating the oven up to said predetermined temperature with the dutyratio corresponding to said temperature range when said detectedtemperature in the oven is below the predetermined temperature.
 6. Abread making device as claimed in claim 5, wherein said pre-heatingcontrol means is further provided with means for keeping the temperatureof the heated oven at its temperature for a predetermined time periodbefore starting the kneading step.